1 /* linux/net/inet/arp.c 2 * 3 * Version: $Id: arp.c,v 1.99 2001/08/30 22:55:42 davem Exp $ 4 * 5 * Copyright (C) 1994 by Florian La Roche 6 * 7 * This module implements the Address Resolution Protocol ARP (RFC 826), 8 * which is used to convert IP addresses (or in the future maybe other 9 * high-level addresses) into a low-level hardware address (like an Ethernet 10 * address). 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 * 17 * Fixes: 18 * Alan Cox : Removed the Ethernet assumptions in 19 * Florian's code 20 * Alan Cox : Fixed some small errors in the ARP 21 * logic 22 * Alan Cox : Allow >4K in /proc 23 * Alan Cox : Make ARP add its own protocol entry 24 * Ross Martin : Rewrote arp_rcv() and arp_get_info() 25 * Stephen Henson : Add AX25 support to arp_get_info() 26 * Alan Cox : Drop data when a device is downed. 27 * Alan Cox : Use init_timer(). 28 * Alan Cox : Double lock fixes. 29 * Martin Seine : Move the arphdr structure 30 * to if_arp.h for compatibility. 31 * with BSD based programs. 32 * Andrew Tridgell : Added ARP netmask code and 33 * re-arranged proxy handling. 34 * Alan Cox : Changed to use notifiers. 35 * Niibe Yutaka : Reply for this device or proxies only. 36 * Alan Cox : Don't proxy across hardware types! 37 * Jonathan Naylor : Added support for NET/ROM. 38 * Mike Shaver : RFC1122 checks. 39 * Jonathan Naylor : Only lookup the hardware address for 40 * the correct hardware type. 41 * Germano Caronni : Assorted subtle races. 42 * Craig Schlenter : Don't modify permanent entry 43 * during arp_rcv. 44 * Russ Nelson : Tidied up a few bits. 45 * Alexey Kuznetsov: Major changes to caching and behaviour, 46 * eg intelligent arp probing and 47 * generation 48 * of host down events. 49 * Alan Cox : Missing unlock in device events. 50 * Eckes : ARP ioctl control errors. 51 * Alexey Kuznetsov: Arp free fix. 52 * Manuel Rodriguez: Gratuitous ARP. 53 * Jonathan Layes : Added arpd support through kerneld 54 * message queue (960314) 55 * Mike Shaver : /proc/sys/net/ipv4/arp_* support 56 * Mike McLagan : Routing by source 57 * Stuart Cheshire : Metricom and grat arp fixes 58 * *** FOR 2.1 clean this up *** 59 * Lawrence V. Stefani: (08/12/96) Added FDDI support. 60 * Alan Cox : Took the AP1000 nasty FDDI hack and 61 * folded into the mainstream FDDI code. 62 * Ack spit, Linus how did you allow that 63 * one in... 64 * Jes Sorensen : Make FDDI work again in 2.1.x and 65 * clean up the APFDDI & gen. FDDI bits. 66 * Alexey Kuznetsov: new arp state machine; 67 * now it is in net/core/neighbour.c. 68 * Krzysztof Halasa: Added Frame Relay ARP support. 69 * Arnaldo C. Melo : convert /proc/net/arp to seq_file 70 * Shmulik Hen: Split arp_send to arp_create and 71 * arp_xmit so intermediate drivers like 72 * bonding can change the skb before 73 * sending (e.g. insert 8021q tag). 74 * Harald Welte : convert to make use of jenkins hash 75 */ 76 77 #include <linux/module.h> 78 #include <linux/types.h> 79 #include <linux/string.h> 80 #include <linux/kernel.h> 81 #include <linux/sched.h> 82 #include <linux/config.h> 83 #include <linux/socket.h> 84 #include <linux/sockios.h> 85 #include <linux/errno.h> 86 #include <linux/in.h> 87 #include <linux/mm.h> 88 #include <linux/inet.h> 89 #include <linux/inetdevice.h> 90 #include <linux/netdevice.h> 91 #include <linux/etherdevice.h> 92 #include <linux/fddidevice.h> 93 #include <linux/if_arp.h> 94 #include <linux/trdevice.h> 95 #include <linux/skbuff.h> 96 #include <linux/proc_fs.h> 97 #include <linux/seq_file.h> 98 #include <linux/stat.h> 99 #include <linux/init.h> 100 #include <linux/net.h> 101 #include <linux/rcupdate.h> 102 #include <linux/jhash.h> 103 #ifdef CONFIG_SYSCTL 104 #include <linux/sysctl.h> 105 #endif 106 107 #include <net/ip.h> 108 #include <net/icmp.h> 109 #include <net/route.h> 110 #include <net/protocol.h> 111 #include <net/tcp.h> 112 #include <net/sock.h> 113 #include <net/arp.h> 114 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 115 #include <net/ax25.h> 116 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 117 #include <net/netrom.h> 118 #endif 119 #endif 120 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 121 #include <net/atmclip.h> 122 struct neigh_table *clip_tbl_hook; 123 #endif 124 125 #include <asm/system.h> 126 #include <asm/uaccess.h> 127 128 #include <linux/netfilter_arp.h> 129 130 /* 131 * Interface to generic neighbour cache. 132 */ 133 static u32 arp_hash(const void *pkey, const struct net_device *dev); 134 static int arp_constructor(struct neighbour *neigh); 135 static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); 136 static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); 137 static void parp_redo(struct sk_buff *skb); 138 139 static struct neigh_ops arp_generic_ops = { 140 .family = AF_INET, 141 .solicit = arp_solicit, 142 .error_report = arp_error_report, 143 .output = neigh_resolve_output, 144 .connected_output = neigh_connected_output, 145 .hh_output = dev_queue_xmit, 146 .queue_xmit = dev_queue_xmit, 147 }; 148 149 static struct neigh_ops arp_hh_ops = { 150 .family = AF_INET, 151 .solicit = arp_solicit, 152 .error_report = arp_error_report, 153 .output = neigh_resolve_output, 154 .connected_output = neigh_resolve_output, 155 .hh_output = dev_queue_xmit, 156 .queue_xmit = dev_queue_xmit, 157 }; 158 159 static struct neigh_ops arp_direct_ops = { 160 .family = AF_INET, 161 .output = dev_queue_xmit, 162 .connected_output = dev_queue_xmit, 163 .hh_output = dev_queue_xmit, 164 .queue_xmit = dev_queue_xmit, 165 }; 166 167 struct neigh_ops arp_broken_ops = { 168 .family = AF_INET, 169 .solicit = arp_solicit, 170 .error_report = arp_error_report, 171 .output = neigh_compat_output, 172 .connected_output = neigh_compat_output, 173 .hh_output = dev_queue_xmit, 174 .queue_xmit = dev_queue_xmit, 175 }; 176 177 struct neigh_table arp_tbl = { 178 .family = AF_INET, 179 .entry_size = sizeof(struct neighbour) + 4, 180 .key_len = 4, 181 .hash = arp_hash, 182 .constructor = arp_constructor, 183 .proxy_redo = parp_redo, 184 .id = "arp_cache", 185 .parms = { 186 .tbl = &arp_tbl, 187 .base_reachable_time = 30 * HZ, 188 .retrans_time = 1 * HZ, 189 .gc_staletime = 60 * HZ, 190 .reachable_time = 30 * HZ, 191 .delay_probe_time = 5 * HZ, 192 .queue_len = 3, 193 .ucast_probes = 3, 194 .mcast_probes = 3, 195 .anycast_delay = 1 * HZ, 196 .proxy_delay = (8 * HZ) / 10, 197 .proxy_qlen = 64, 198 .locktime = 1 * HZ, 199 }, 200 .gc_interval = 30 * HZ, 201 .gc_thresh1 = 128, 202 .gc_thresh2 = 512, 203 .gc_thresh3 = 1024, 204 }; 205 206 int arp_mc_map(u32 addr, u8 *haddr, struct net_device *dev, int dir) 207 { 208 switch (dev->type) { 209 case ARPHRD_ETHER: 210 case ARPHRD_FDDI: 211 case ARPHRD_IEEE802: 212 ip_eth_mc_map(addr, haddr); 213 return 0; 214 case ARPHRD_IEEE802_TR: 215 ip_tr_mc_map(addr, haddr); 216 return 0; 217 case ARPHRD_INFINIBAND: 218 ip_ib_mc_map(addr, haddr); 219 return 0; 220 default: 221 if (dir) { 222 memcpy(haddr, dev->broadcast, dev->addr_len); 223 return 0; 224 } 225 } 226 return -EINVAL; 227 } 228 229 230 static u32 arp_hash(const void *pkey, const struct net_device *dev) 231 { 232 return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd); 233 } 234 235 static int arp_constructor(struct neighbour *neigh) 236 { 237 u32 addr = *(u32*)neigh->primary_key; 238 struct net_device *dev = neigh->dev; 239 struct in_device *in_dev; 240 struct neigh_parms *parms; 241 242 neigh->type = inet_addr_type(addr); 243 244 rcu_read_lock(); 245 in_dev = __in_dev_get_rcu(dev); 246 if (in_dev == NULL) { 247 rcu_read_unlock(); 248 return -EINVAL; 249 } 250 251 parms = in_dev->arp_parms; 252 __neigh_parms_put(neigh->parms); 253 neigh->parms = neigh_parms_clone(parms); 254 rcu_read_unlock(); 255 256 if (dev->hard_header == NULL) { 257 neigh->nud_state = NUD_NOARP; 258 neigh->ops = &arp_direct_ops; 259 neigh->output = neigh->ops->queue_xmit; 260 } else { 261 /* Good devices (checked by reading texts, but only Ethernet is 262 tested) 263 264 ARPHRD_ETHER: (ethernet, apfddi) 265 ARPHRD_FDDI: (fddi) 266 ARPHRD_IEEE802: (tr) 267 ARPHRD_METRICOM: (strip) 268 ARPHRD_ARCNET: 269 etc. etc. etc. 270 271 ARPHRD_IPDDP will also work, if author repairs it. 272 I did not it, because this driver does not work even 273 in old paradigm. 274 */ 275 276 #if 1 277 /* So... these "amateur" devices are hopeless. 278 The only thing, that I can say now: 279 It is very sad that we need to keep ugly obsolete 280 code to make them happy. 281 282 They should be moved to more reasonable state, now 283 they use rebuild_header INSTEAD OF hard_start_xmit!!! 284 Besides that, they are sort of out of date 285 (a lot of redundant clones/copies, useless in 2.1), 286 I wonder why people believe that they work. 287 */ 288 switch (dev->type) { 289 default: 290 break; 291 case ARPHRD_ROSE: 292 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 293 case ARPHRD_AX25: 294 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 295 case ARPHRD_NETROM: 296 #endif 297 neigh->ops = &arp_broken_ops; 298 neigh->output = neigh->ops->output; 299 return 0; 300 #endif 301 ;} 302 #endif 303 if (neigh->type == RTN_MULTICAST) { 304 neigh->nud_state = NUD_NOARP; 305 arp_mc_map(addr, neigh->ha, dev, 1); 306 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 307 neigh->nud_state = NUD_NOARP; 308 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 309 } else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) { 310 neigh->nud_state = NUD_NOARP; 311 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 312 } 313 if (dev->hard_header_cache) 314 neigh->ops = &arp_hh_ops; 315 else 316 neigh->ops = &arp_generic_ops; 317 if (neigh->nud_state&NUD_VALID) 318 neigh->output = neigh->ops->connected_output; 319 else 320 neigh->output = neigh->ops->output; 321 } 322 return 0; 323 } 324 325 static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) 326 { 327 dst_link_failure(skb); 328 kfree_skb(skb); 329 } 330 331 static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) 332 { 333 u32 saddr = 0; 334 u8 *dst_ha = NULL; 335 struct net_device *dev = neigh->dev; 336 u32 target = *(u32*)neigh->primary_key; 337 int probes = atomic_read(&neigh->probes); 338 struct in_device *in_dev = in_dev_get(dev); 339 340 if (!in_dev) 341 return; 342 343 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { 344 default: 345 case 0: /* By default announce any local IP */ 346 if (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL) 347 saddr = skb->nh.iph->saddr; 348 break; 349 case 1: /* Restrict announcements of saddr in same subnet */ 350 if (!skb) 351 break; 352 saddr = skb->nh.iph->saddr; 353 if (inet_addr_type(saddr) == RTN_LOCAL) { 354 /* saddr should be known to target */ 355 if (inet_addr_onlink(in_dev, target, saddr)) 356 break; 357 } 358 saddr = 0; 359 break; 360 case 2: /* Avoid secondary IPs, get a primary/preferred one */ 361 break; 362 } 363 364 if (in_dev) 365 in_dev_put(in_dev); 366 if (!saddr) 367 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); 368 369 if ((probes -= neigh->parms->ucast_probes) < 0) { 370 if (!(neigh->nud_state&NUD_VALID)) 371 printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n"); 372 dst_ha = neigh->ha; 373 read_lock_bh(&neigh->lock); 374 } else if ((probes -= neigh->parms->app_probes) < 0) { 375 #ifdef CONFIG_ARPD 376 neigh_app_ns(neigh); 377 #endif 378 return; 379 } 380 381 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, 382 dst_ha, dev->dev_addr, NULL); 383 if (dst_ha) 384 read_unlock_bh(&neigh->lock); 385 } 386 387 static int arp_ignore(struct in_device *in_dev, struct net_device *dev, 388 u32 sip, u32 tip) 389 { 390 int scope; 391 392 switch (IN_DEV_ARP_IGNORE(in_dev)) { 393 case 0: /* Reply, the tip is already validated */ 394 return 0; 395 case 1: /* Reply only if tip is configured on the incoming interface */ 396 sip = 0; 397 scope = RT_SCOPE_HOST; 398 break; 399 case 2: /* 400 * Reply only if tip is configured on the incoming interface 401 * and is in same subnet as sip 402 */ 403 scope = RT_SCOPE_HOST; 404 break; 405 case 3: /* Do not reply for scope host addresses */ 406 sip = 0; 407 scope = RT_SCOPE_LINK; 408 dev = NULL; 409 break; 410 case 4: /* Reserved */ 411 case 5: 412 case 6: 413 case 7: 414 return 0; 415 case 8: /* Do not reply */ 416 return 1; 417 default: 418 return 0; 419 } 420 return !inet_confirm_addr(dev, sip, tip, scope); 421 } 422 423 static int arp_filter(__u32 sip, __u32 tip, struct net_device *dev) 424 { 425 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip, 426 .saddr = tip } } }; 427 struct rtable *rt; 428 int flag = 0; 429 /*unsigned long now; */ 430 431 if (ip_route_output_key(&rt, &fl) < 0) 432 return 1; 433 if (rt->u.dst.dev != dev) { 434 NET_INC_STATS_BH(LINUX_MIB_ARPFILTER); 435 flag = 1; 436 } 437 ip_rt_put(rt); 438 return flag; 439 } 440 441 /* OBSOLETE FUNCTIONS */ 442 443 /* 444 * Find an arp mapping in the cache. If not found, post a request. 445 * 446 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, 447 * even if it exists. It is supposed that skb->dev was mangled 448 * by a virtual device (eql, shaper). Nobody but broken devices 449 * is allowed to use this function, it is scheduled to be removed. --ANK 450 */ 451 452 static int arp_set_predefined(int addr_hint, unsigned char * haddr, u32 paddr, struct net_device * dev) 453 { 454 switch (addr_hint) { 455 case RTN_LOCAL: 456 printk(KERN_DEBUG "ARP: arp called for own IP address\n"); 457 memcpy(haddr, dev->dev_addr, dev->addr_len); 458 return 1; 459 case RTN_MULTICAST: 460 arp_mc_map(paddr, haddr, dev, 1); 461 return 1; 462 case RTN_BROADCAST: 463 memcpy(haddr, dev->broadcast, dev->addr_len); 464 return 1; 465 } 466 return 0; 467 } 468 469 470 int arp_find(unsigned char *haddr, struct sk_buff *skb) 471 { 472 struct net_device *dev = skb->dev; 473 u32 paddr; 474 struct neighbour *n; 475 476 if (!skb->dst) { 477 printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); 478 kfree_skb(skb); 479 return 1; 480 } 481 482 paddr = ((struct rtable*)skb->dst)->rt_gateway; 483 484 if (arp_set_predefined(inet_addr_type(paddr), haddr, paddr, dev)) 485 return 0; 486 487 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); 488 489 if (n) { 490 n->used = jiffies; 491 if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) { 492 read_lock_bh(&n->lock); 493 memcpy(haddr, n->ha, dev->addr_len); 494 read_unlock_bh(&n->lock); 495 neigh_release(n); 496 return 0; 497 } 498 neigh_release(n); 499 } else 500 kfree_skb(skb); 501 return 1; 502 } 503 504 /* END OF OBSOLETE FUNCTIONS */ 505 506 int arp_bind_neighbour(struct dst_entry *dst) 507 { 508 struct net_device *dev = dst->dev; 509 struct neighbour *n = dst->neighbour; 510 511 if (dev == NULL) 512 return -EINVAL; 513 if (n == NULL) { 514 u32 nexthop = ((struct rtable*)dst)->rt_gateway; 515 if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT)) 516 nexthop = 0; 517 n = __neigh_lookup_errno( 518 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 519 dev->type == ARPHRD_ATM ? clip_tbl_hook : 520 #endif 521 &arp_tbl, &nexthop, dev); 522 if (IS_ERR(n)) 523 return PTR_ERR(n); 524 dst->neighbour = n; 525 } 526 return 0; 527 } 528 529 /* 530 * Check if we can use proxy ARP for this path 531 */ 532 533 static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt) 534 { 535 struct in_device *out_dev; 536 int imi, omi = -1; 537 538 if (!IN_DEV_PROXY_ARP(in_dev)) 539 return 0; 540 541 if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0) 542 return 1; 543 if (imi == -1) 544 return 0; 545 546 /* place to check for proxy_arp for routes */ 547 548 if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) { 549 omi = IN_DEV_MEDIUM_ID(out_dev); 550 in_dev_put(out_dev); 551 } 552 return (omi != imi && omi != -1); 553 } 554 555 /* 556 * Interface to link layer: send routine and receive handler. 557 */ 558 559 /* 560 * Create an arp packet. If (dest_hw == NULL), we create a broadcast 561 * message. 562 */ 563 struct sk_buff *arp_create(int type, int ptype, u32 dest_ip, 564 struct net_device *dev, u32 src_ip, 565 unsigned char *dest_hw, unsigned char *src_hw, 566 unsigned char *target_hw) 567 { 568 struct sk_buff *skb; 569 struct arphdr *arp; 570 unsigned char *arp_ptr; 571 572 /* 573 * Allocate a buffer 574 */ 575 576 skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4) 577 + LL_RESERVED_SPACE(dev), GFP_ATOMIC); 578 if (skb == NULL) 579 return NULL; 580 581 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 582 skb->nh.raw = skb->data; 583 arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4)); 584 skb->dev = dev; 585 skb->protocol = htons(ETH_P_ARP); 586 if (src_hw == NULL) 587 src_hw = dev->dev_addr; 588 if (dest_hw == NULL) 589 dest_hw = dev->broadcast; 590 591 /* 592 * Fill the device header for the ARP frame 593 */ 594 if (dev->hard_header && 595 dev->hard_header(skb,dev,ptype,dest_hw,src_hw,skb->len) < 0) 596 goto out; 597 598 /* 599 * Fill out the arp protocol part. 600 * 601 * The arp hardware type should match the device type, except for FDDI, 602 * which (according to RFC 1390) should always equal 1 (Ethernet). 603 */ 604 /* 605 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the 606 * DIX code for the protocol. Make these device structure fields. 607 */ 608 switch (dev->type) { 609 default: 610 arp->ar_hrd = htons(dev->type); 611 arp->ar_pro = htons(ETH_P_IP); 612 break; 613 614 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 615 case ARPHRD_AX25: 616 arp->ar_hrd = htons(ARPHRD_AX25); 617 arp->ar_pro = htons(AX25_P_IP); 618 break; 619 620 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 621 case ARPHRD_NETROM: 622 arp->ar_hrd = htons(ARPHRD_NETROM); 623 arp->ar_pro = htons(AX25_P_IP); 624 break; 625 #endif 626 #endif 627 628 #ifdef CONFIG_FDDI 629 case ARPHRD_FDDI: 630 arp->ar_hrd = htons(ARPHRD_ETHER); 631 arp->ar_pro = htons(ETH_P_IP); 632 break; 633 #endif 634 #ifdef CONFIG_TR 635 case ARPHRD_IEEE802_TR: 636 arp->ar_hrd = htons(ARPHRD_IEEE802); 637 arp->ar_pro = htons(ETH_P_IP); 638 break; 639 #endif 640 } 641 642 arp->ar_hln = dev->addr_len; 643 arp->ar_pln = 4; 644 arp->ar_op = htons(type); 645 646 arp_ptr=(unsigned char *)(arp+1); 647 648 memcpy(arp_ptr, src_hw, dev->addr_len); 649 arp_ptr+=dev->addr_len; 650 memcpy(arp_ptr, &src_ip,4); 651 arp_ptr+=4; 652 if (target_hw != NULL) 653 memcpy(arp_ptr, target_hw, dev->addr_len); 654 else 655 memset(arp_ptr, 0, dev->addr_len); 656 arp_ptr+=dev->addr_len; 657 memcpy(arp_ptr, &dest_ip, 4); 658 659 return skb; 660 661 out: 662 kfree_skb(skb); 663 return NULL; 664 } 665 666 /* 667 * Send an arp packet. 668 */ 669 void arp_xmit(struct sk_buff *skb) 670 { 671 /* Send it off, maybe filter it using firewalling first. */ 672 NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); 673 } 674 675 /* 676 * Create and send an arp packet. 677 */ 678 void arp_send(int type, int ptype, u32 dest_ip, 679 struct net_device *dev, u32 src_ip, 680 unsigned char *dest_hw, unsigned char *src_hw, 681 unsigned char *target_hw) 682 { 683 struct sk_buff *skb; 684 685 /* 686 * No arp on this interface. 687 */ 688 689 if (dev->flags&IFF_NOARP) 690 return; 691 692 skb = arp_create(type, ptype, dest_ip, dev, src_ip, 693 dest_hw, src_hw, target_hw); 694 if (skb == NULL) { 695 return; 696 } 697 698 arp_xmit(skb); 699 } 700 701 /* 702 * Process an arp request. 703 */ 704 705 static int arp_process(struct sk_buff *skb) 706 { 707 struct net_device *dev = skb->dev; 708 struct in_device *in_dev = in_dev_get(dev); 709 struct arphdr *arp; 710 unsigned char *arp_ptr; 711 struct rtable *rt; 712 unsigned char *sha, *tha; 713 u32 sip, tip; 714 u16 dev_type = dev->type; 715 int addr_type; 716 struct neighbour *n; 717 718 /* arp_rcv below verifies the ARP header and verifies the device 719 * is ARP'able. 720 */ 721 722 if (in_dev == NULL) 723 goto out; 724 725 arp = skb->nh.arph; 726 727 switch (dev_type) { 728 default: 729 if (arp->ar_pro != htons(ETH_P_IP) || 730 htons(dev_type) != arp->ar_hrd) 731 goto out; 732 break; 733 #ifdef CONFIG_NET_ETHERNET 734 case ARPHRD_ETHER: 735 #endif 736 #ifdef CONFIG_TR 737 case ARPHRD_IEEE802_TR: 738 #endif 739 #ifdef CONFIG_FDDI 740 case ARPHRD_FDDI: 741 #endif 742 #ifdef CONFIG_NET_FC 743 case ARPHRD_IEEE802: 744 #endif 745 #if defined(CONFIG_NET_ETHERNET) || defined(CONFIG_TR) || \ 746 defined(CONFIG_FDDI) || defined(CONFIG_NET_FC) 747 /* 748 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 749 * devices, according to RFC 2625) devices will accept ARP 750 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). 751 * This is the case also of FDDI, where the RFC 1390 says that 752 * FDDI devices should accept ARP hardware of (1) Ethernet, 753 * however, to be more robust, we'll accept both 1 (Ethernet) 754 * or 6 (IEEE 802.2) 755 */ 756 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 757 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 758 arp->ar_pro != htons(ETH_P_IP)) 759 goto out; 760 break; 761 #endif 762 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 763 case ARPHRD_AX25: 764 if (arp->ar_pro != htons(AX25_P_IP) || 765 arp->ar_hrd != htons(ARPHRD_AX25)) 766 goto out; 767 break; 768 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 769 case ARPHRD_NETROM: 770 if (arp->ar_pro != htons(AX25_P_IP) || 771 arp->ar_hrd != htons(ARPHRD_NETROM)) 772 goto out; 773 break; 774 #endif 775 #endif 776 } 777 778 /* Understand only these message types */ 779 780 if (arp->ar_op != htons(ARPOP_REPLY) && 781 arp->ar_op != htons(ARPOP_REQUEST)) 782 goto out; 783 784 /* 785 * Extract fields 786 */ 787 arp_ptr= (unsigned char *)(arp+1); 788 sha = arp_ptr; 789 arp_ptr += dev->addr_len; 790 memcpy(&sip, arp_ptr, 4); 791 arp_ptr += 4; 792 tha = arp_ptr; 793 arp_ptr += dev->addr_len; 794 memcpy(&tip, arp_ptr, 4); 795 /* 796 * Check for bad requests for 127.x.x.x and requests for multicast 797 * addresses. If this is one such, delete it. 798 */ 799 if (LOOPBACK(tip) || MULTICAST(tip)) 800 goto out; 801 802 /* 803 * Special case: We must set Frame Relay source Q.922 address 804 */ 805 if (dev_type == ARPHRD_DLCI) 806 sha = dev->broadcast; 807 808 /* 809 * Process entry. The idea here is we want to send a reply if it is a 810 * request for us or if it is a request for someone else that we hold 811 * a proxy for. We want to add an entry to our cache if it is a reply 812 * to us or if it is a request for our address. 813 * (The assumption for this last is that if someone is requesting our 814 * address, they are probably intending to talk to us, so it saves time 815 * if we cache their address. Their address is also probably not in 816 * our cache, since ours is not in their cache.) 817 * 818 * Putting this another way, we only care about replies if they are to 819 * us, in which case we add them to the cache. For requests, we care 820 * about those for us and those for our proxies. We reply to both, 821 * and in the case of requests for us we add the requester to the arp 822 * cache. 823 */ 824 825 /* Special case: IPv4 duplicate address detection packet (RFC2131) */ 826 if (sip == 0) { 827 if (arp->ar_op == htons(ARPOP_REQUEST) && 828 inet_addr_type(tip) == RTN_LOCAL && 829 !arp_ignore(in_dev,dev,sip,tip)) 830 arp_send(ARPOP_REPLY,ETH_P_ARP,tip,dev,tip,sha,dev->dev_addr,dev->dev_addr); 831 goto out; 832 } 833 834 if (arp->ar_op == htons(ARPOP_REQUEST) && 835 ip_route_input(skb, tip, sip, 0, dev) == 0) { 836 837 rt = (struct rtable*)skb->dst; 838 addr_type = rt->rt_type; 839 840 if (addr_type == RTN_LOCAL) { 841 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 842 if (n) { 843 int dont_send = 0; 844 845 if (!dont_send) 846 dont_send |= arp_ignore(in_dev,dev,sip,tip); 847 if (!dont_send && IN_DEV_ARPFILTER(in_dev)) 848 dont_send |= arp_filter(sip,tip,dev); 849 if (!dont_send) 850 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 851 852 neigh_release(n); 853 } 854 goto out; 855 } else if (IN_DEV_FORWARD(in_dev)) { 856 if ((rt->rt_flags&RTCF_DNAT) || 857 (addr_type == RTN_UNICAST && rt->u.dst.dev != dev && 858 (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &tip, dev, 0)))) { 859 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 860 if (n) 861 neigh_release(n); 862 863 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || 864 skb->pkt_type == PACKET_HOST || 865 in_dev->arp_parms->proxy_delay == 0) { 866 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 867 } else { 868 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb); 869 in_dev_put(in_dev); 870 return 0; 871 } 872 goto out; 873 } 874 } 875 } 876 877 /* Update our ARP tables */ 878 879 n = __neigh_lookup(&arp_tbl, &sip, dev, 0); 880 881 #ifdef CONFIG_IP_ACCEPT_UNSOLICITED_ARP 882 /* Unsolicited ARP is not accepted by default. 883 It is possible, that this option should be enabled for some 884 devices (strip is candidate) 885 */ 886 if (n == NULL && 887 arp->ar_op == htons(ARPOP_REPLY) && 888 inet_addr_type(sip) == RTN_UNICAST) 889 n = __neigh_lookup(&arp_tbl, &sip, dev, -1); 890 #endif 891 892 if (n) { 893 int state = NUD_REACHABLE; 894 int override; 895 896 /* If several different ARP replies follows back-to-back, 897 use the FIRST one. It is possible, if several proxy 898 agents are active. Taking the first reply prevents 899 arp trashing and chooses the fastest router. 900 */ 901 override = time_after(jiffies, n->updated + n->parms->locktime); 902 903 /* Broadcast replies and request packets 904 do not assert neighbour reachability. 905 */ 906 if (arp->ar_op != htons(ARPOP_REPLY) || 907 skb->pkt_type != PACKET_HOST) 908 state = NUD_STALE; 909 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0); 910 neigh_release(n); 911 } 912 913 out: 914 if (in_dev) 915 in_dev_put(in_dev); 916 kfree_skb(skb); 917 return 0; 918 } 919 920 static void parp_redo(struct sk_buff *skb) 921 { 922 arp_process(skb); 923 } 924 925 926 /* 927 * Receive an arp request from the device layer. 928 */ 929 930 int arp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) 931 { 932 struct arphdr *arp; 933 934 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ 935 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 936 (2 * dev->addr_len) + 937 (2 * sizeof(u32))))) 938 goto freeskb; 939 940 arp = skb->nh.arph; 941 if (arp->ar_hln != dev->addr_len || 942 dev->flags & IFF_NOARP || 943 skb->pkt_type == PACKET_OTHERHOST || 944 skb->pkt_type == PACKET_LOOPBACK || 945 arp->ar_pln != 4) 946 goto freeskb; 947 948 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 949 goto out_of_mem; 950 951 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 952 953 return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); 954 955 freeskb: 956 kfree_skb(skb); 957 out_of_mem: 958 return 0; 959 } 960 961 /* 962 * User level interface (ioctl) 963 */ 964 965 /* 966 * Set (create) an ARP cache entry. 967 */ 968 969 static int arp_req_set(struct arpreq *r, struct net_device * dev) 970 { 971 u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 972 struct neighbour *neigh; 973 int err; 974 975 if (r->arp_flags&ATF_PUBL) { 976 u32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr; 977 if (mask && mask != 0xFFFFFFFF) 978 return -EINVAL; 979 if (!dev && (r->arp_flags & ATF_COM)) { 980 dev = dev_getbyhwaddr(r->arp_ha.sa_family, r->arp_ha.sa_data); 981 if (!dev) 982 return -ENODEV; 983 } 984 if (mask) { 985 if (pneigh_lookup(&arp_tbl, &ip, dev, 1) == NULL) 986 return -ENOBUFS; 987 return 0; 988 } 989 if (dev == NULL) { 990 ipv4_devconf.proxy_arp = 1; 991 return 0; 992 } 993 if (__in_dev_get_rtnl(dev)) { 994 __in_dev_get_rtnl(dev)->cnf.proxy_arp = 1; 995 return 0; 996 } 997 return -ENXIO; 998 } 999 1000 if (r->arp_flags & ATF_PERM) 1001 r->arp_flags |= ATF_COM; 1002 if (dev == NULL) { 1003 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1004 .tos = RTO_ONLINK } } }; 1005 struct rtable * rt; 1006 if ((err = ip_route_output_key(&rt, &fl)) != 0) 1007 return err; 1008 dev = rt->u.dst.dev; 1009 ip_rt_put(rt); 1010 if (!dev) 1011 return -EINVAL; 1012 } 1013 switch (dev->type) { 1014 #ifdef CONFIG_FDDI 1015 case ARPHRD_FDDI: 1016 /* 1017 * According to RFC 1390, FDDI devices should accept ARP 1018 * hardware types of 1 (Ethernet). However, to be more 1019 * robust, we'll accept hardware types of either 1 (Ethernet) 1020 * or 6 (IEEE 802.2). 1021 */ 1022 if (r->arp_ha.sa_family != ARPHRD_FDDI && 1023 r->arp_ha.sa_family != ARPHRD_ETHER && 1024 r->arp_ha.sa_family != ARPHRD_IEEE802) 1025 return -EINVAL; 1026 break; 1027 #endif 1028 default: 1029 if (r->arp_ha.sa_family != dev->type) 1030 return -EINVAL; 1031 break; 1032 } 1033 1034 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); 1035 err = PTR_ERR(neigh); 1036 if (!IS_ERR(neigh)) { 1037 unsigned state = NUD_STALE; 1038 if (r->arp_flags & ATF_PERM) 1039 state = NUD_PERMANENT; 1040 err = neigh_update(neigh, (r->arp_flags&ATF_COM) ? 1041 r->arp_ha.sa_data : NULL, state, 1042 NEIGH_UPDATE_F_OVERRIDE| 1043 NEIGH_UPDATE_F_ADMIN); 1044 neigh_release(neigh); 1045 } 1046 return err; 1047 } 1048 1049 static unsigned arp_state_to_flags(struct neighbour *neigh) 1050 { 1051 unsigned flags = 0; 1052 if (neigh->nud_state&NUD_PERMANENT) 1053 flags = ATF_PERM|ATF_COM; 1054 else if (neigh->nud_state&NUD_VALID) 1055 flags = ATF_COM; 1056 return flags; 1057 } 1058 1059 /* 1060 * Get an ARP cache entry. 1061 */ 1062 1063 static int arp_req_get(struct arpreq *r, struct net_device *dev) 1064 { 1065 u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1066 struct neighbour *neigh; 1067 int err = -ENXIO; 1068 1069 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1070 if (neigh) { 1071 read_lock_bh(&neigh->lock); 1072 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); 1073 r->arp_flags = arp_state_to_flags(neigh); 1074 read_unlock_bh(&neigh->lock); 1075 r->arp_ha.sa_family = dev->type; 1076 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); 1077 neigh_release(neigh); 1078 err = 0; 1079 } 1080 return err; 1081 } 1082 1083 static int arp_req_delete(struct arpreq *r, struct net_device * dev) 1084 { 1085 int err; 1086 u32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1087 struct neighbour *neigh; 1088 1089 if (r->arp_flags & ATF_PUBL) { 1090 u32 mask = 1091 ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1092 if (mask == 0xFFFFFFFF) 1093 return pneigh_delete(&arp_tbl, &ip, dev); 1094 if (mask == 0) { 1095 if (dev == NULL) { 1096 ipv4_devconf.proxy_arp = 0; 1097 return 0; 1098 } 1099 if (__in_dev_get_rtnl(dev)) { 1100 __in_dev_get_rtnl(dev)->cnf.proxy_arp = 0; 1101 return 0; 1102 } 1103 return -ENXIO; 1104 } 1105 return -EINVAL; 1106 } 1107 1108 if (dev == NULL) { 1109 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1110 .tos = RTO_ONLINK } } }; 1111 struct rtable * rt; 1112 if ((err = ip_route_output_key(&rt, &fl)) != 0) 1113 return err; 1114 dev = rt->u.dst.dev; 1115 ip_rt_put(rt); 1116 if (!dev) 1117 return -EINVAL; 1118 } 1119 err = -ENXIO; 1120 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1121 if (neigh) { 1122 if (neigh->nud_state&~NUD_NOARP) 1123 err = neigh_update(neigh, NULL, NUD_FAILED, 1124 NEIGH_UPDATE_F_OVERRIDE| 1125 NEIGH_UPDATE_F_ADMIN); 1126 neigh_release(neigh); 1127 } 1128 return err; 1129 } 1130 1131 /* 1132 * Handle an ARP layer I/O control request. 1133 */ 1134 1135 int arp_ioctl(unsigned int cmd, void __user *arg) 1136 { 1137 int err; 1138 struct arpreq r; 1139 struct net_device *dev = NULL; 1140 1141 switch (cmd) { 1142 case SIOCDARP: 1143 case SIOCSARP: 1144 if (!capable(CAP_NET_ADMIN)) 1145 return -EPERM; 1146 case SIOCGARP: 1147 err = copy_from_user(&r, arg, sizeof(struct arpreq)); 1148 if (err) 1149 return -EFAULT; 1150 break; 1151 default: 1152 return -EINVAL; 1153 } 1154 1155 if (r.arp_pa.sa_family != AF_INET) 1156 return -EPFNOSUPPORT; 1157 1158 if (!(r.arp_flags & ATF_PUBL) && 1159 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB))) 1160 return -EINVAL; 1161 if (!(r.arp_flags & ATF_NETMASK)) 1162 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = 1163 htonl(0xFFFFFFFFUL); 1164 rtnl_lock(); 1165 if (r.arp_dev[0]) { 1166 err = -ENODEV; 1167 if ((dev = __dev_get_by_name(r.arp_dev)) == NULL) 1168 goto out; 1169 1170 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ 1171 if (!r.arp_ha.sa_family) 1172 r.arp_ha.sa_family = dev->type; 1173 err = -EINVAL; 1174 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) 1175 goto out; 1176 } else if (cmd == SIOCGARP) { 1177 err = -ENODEV; 1178 goto out; 1179 } 1180 1181 switch(cmd) { 1182 case SIOCDARP: 1183 err = arp_req_delete(&r, dev); 1184 break; 1185 case SIOCSARP: 1186 err = arp_req_set(&r, dev); 1187 break; 1188 case SIOCGARP: 1189 err = arp_req_get(&r, dev); 1190 if (!err && copy_to_user(arg, &r, sizeof(r))) 1191 err = -EFAULT; 1192 break; 1193 } 1194 out: 1195 rtnl_unlock(); 1196 return err; 1197 } 1198 1199 static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1200 { 1201 struct net_device *dev = ptr; 1202 1203 switch (event) { 1204 case NETDEV_CHANGEADDR: 1205 neigh_changeaddr(&arp_tbl, dev); 1206 rt_cache_flush(0); 1207 break; 1208 default: 1209 break; 1210 } 1211 1212 return NOTIFY_DONE; 1213 } 1214 1215 static struct notifier_block arp_netdev_notifier = { 1216 .notifier_call = arp_netdev_event, 1217 }; 1218 1219 /* Note, that it is not on notifier chain. 1220 It is necessary, that this routine was called after route cache will be 1221 flushed. 1222 */ 1223 void arp_ifdown(struct net_device *dev) 1224 { 1225 neigh_ifdown(&arp_tbl, dev); 1226 } 1227 1228 1229 /* 1230 * Called once on startup. 1231 */ 1232 1233 static struct packet_type arp_packet_type = { 1234 .type = __constant_htons(ETH_P_ARP), 1235 .func = arp_rcv, 1236 }; 1237 1238 static int arp_proc_init(void); 1239 1240 void __init arp_init(void) 1241 { 1242 neigh_table_init(&arp_tbl); 1243 1244 dev_add_pack(&arp_packet_type); 1245 arp_proc_init(); 1246 #ifdef CONFIG_SYSCTL 1247 neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4, 1248 NET_IPV4_NEIGH, "ipv4", NULL, NULL); 1249 #endif 1250 register_netdevice_notifier(&arp_netdev_notifier); 1251 } 1252 1253 #ifdef CONFIG_PROC_FS 1254 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1255 1256 /* ------------------------------------------------------------------------ */ 1257 /* 1258 * ax25 -> ASCII conversion 1259 */ 1260 static char *ax2asc2(ax25_address *a, char *buf) 1261 { 1262 char c, *s; 1263 int n; 1264 1265 for (n = 0, s = buf; n < 6; n++) { 1266 c = (a->ax25_call[n] >> 1) & 0x7F; 1267 1268 if (c != ' ') *s++ = c; 1269 } 1270 1271 *s++ = '-'; 1272 1273 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) { 1274 *s++ = '1'; 1275 n -= 10; 1276 } 1277 1278 *s++ = n + '0'; 1279 *s++ = '\0'; 1280 1281 if (*buf == '\0' || *buf == '-') 1282 return "*"; 1283 1284 return buf; 1285 1286 } 1287 #endif /* CONFIG_AX25 */ 1288 1289 #define HBUFFERLEN 30 1290 1291 static void arp_format_neigh_entry(struct seq_file *seq, 1292 struct neighbour *n) 1293 { 1294 char hbuffer[HBUFFERLEN]; 1295 const char hexbuf[] = "0123456789ABCDEF"; 1296 int k, j; 1297 char tbuf[16]; 1298 struct net_device *dev = n->dev; 1299 int hatype = dev->type; 1300 1301 read_lock(&n->lock); 1302 /* Convert hardware address to XX:XX:XX:XX ... form. */ 1303 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1304 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) 1305 ax2asc2((ax25_address *)n->ha, hbuffer); 1306 else { 1307 #endif 1308 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { 1309 hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15]; 1310 hbuffer[k++] = hexbuf[n->ha[j] & 15]; 1311 hbuffer[k++] = ':'; 1312 } 1313 hbuffer[--k] = 0; 1314 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1315 } 1316 #endif 1317 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key)); 1318 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1319 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); 1320 read_unlock(&n->lock); 1321 } 1322 1323 static void arp_format_pneigh_entry(struct seq_file *seq, 1324 struct pneigh_entry *n) 1325 { 1326 struct net_device *dev = n->dev; 1327 int hatype = dev ? dev->type : 0; 1328 char tbuf[16]; 1329 1330 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key)); 1331 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1332 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", 1333 dev ? dev->name : "*"); 1334 } 1335 1336 static int arp_seq_show(struct seq_file *seq, void *v) 1337 { 1338 if (v == SEQ_START_TOKEN) { 1339 seq_puts(seq, "IP address HW type Flags " 1340 "HW address Mask Device\n"); 1341 } else { 1342 struct neigh_seq_state *state = seq->private; 1343 1344 if (state->flags & NEIGH_SEQ_IS_PNEIGH) 1345 arp_format_pneigh_entry(seq, v); 1346 else 1347 arp_format_neigh_entry(seq, v); 1348 } 1349 1350 return 0; 1351 } 1352 1353 static void *arp_seq_start(struct seq_file *seq, loff_t *pos) 1354 { 1355 /* Don't want to confuse "arp -a" w/ magic entries, 1356 * so we tell the generic iterator to skip NUD_NOARP. 1357 */ 1358 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); 1359 } 1360 1361 /* ------------------------------------------------------------------------ */ 1362 1363 static struct seq_operations arp_seq_ops = { 1364 .start = arp_seq_start, 1365 .next = neigh_seq_next, 1366 .stop = neigh_seq_stop, 1367 .show = arp_seq_show, 1368 }; 1369 1370 static int arp_seq_open(struct inode *inode, struct file *file) 1371 { 1372 struct seq_file *seq; 1373 int rc = -ENOMEM; 1374 struct neigh_seq_state *s = kmalloc(sizeof(*s), GFP_KERNEL); 1375 1376 if (!s) 1377 goto out; 1378 1379 memset(s, 0, sizeof(*s)); 1380 rc = seq_open(file, &arp_seq_ops); 1381 if (rc) 1382 goto out_kfree; 1383 1384 seq = file->private_data; 1385 seq->private = s; 1386 out: 1387 return rc; 1388 out_kfree: 1389 kfree(s); 1390 goto out; 1391 } 1392 1393 static struct file_operations arp_seq_fops = { 1394 .owner = THIS_MODULE, 1395 .open = arp_seq_open, 1396 .read = seq_read, 1397 .llseek = seq_lseek, 1398 .release = seq_release_private, 1399 }; 1400 1401 static int __init arp_proc_init(void) 1402 { 1403 if (!proc_net_fops_create("arp", S_IRUGO, &arp_seq_fops)) 1404 return -ENOMEM; 1405 return 0; 1406 } 1407 1408 #else /* CONFIG_PROC_FS */ 1409 1410 static int __init arp_proc_init(void) 1411 { 1412 return 0; 1413 } 1414 1415 #endif /* CONFIG_PROC_FS */ 1416 1417 EXPORT_SYMBOL(arp_broken_ops); 1418 EXPORT_SYMBOL(arp_find); 1419 EXPORT_SYMBOL(arp_rcv); 1420 EXPORT_SYMBOL(arp_create); 1421 EXPORT_SYMBOL(arp_xmit); 1422 EXPORT_SYMBOL(arp_send); 1423 EXPORT_SYMBOL(arp_tbl); 1424 1425 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 1426 EXPORT_SYMBOL(clip_tbl_hook); 1427 #endif 1428